Established deciduous magnolias can be easily killed by transplanting. Maybe instead try to improve the growing conditions where they are now, prune and train them into tree shapes with elevated crowns that fit the street tree situation.

If possible.

We have successfully moved 2 star magnolias over the years but bboy is correct that it is risky. B/c of wrong location by original owner, however, we had no choice. We did it in Fall, after root pruning a month beforehand. Took as large a root ball as possible and gave good attention with the water the next year. Also, we give them a bit of mulch each year. They took several years to gain their vigour but both are very healthy now.

If they receive enough light where they are now, I would agree with bboy and suggest you try improving the conditions; carefully remove any grass that is close to the trunk and competing with them for water; give a good mulch of compost each year, prune out lowest branches etc. Star magnolias can be such beautiful trees it would be a shame to lose them.

Either way, I wish you success!

Bob

Thanks all. We're going to leave them and see if they can make a go of it where they are (it is a sunny location). I'm not hopeful, however. One is in decent shape but has 3 trunks rather than 1 so it will likely be more bushy (although we pruned all the low branches). The other basically has no branches. It is probably 6' tall and the diameter of its trunk is probably 2" max at the base. It is just tall and spindly with 3 small branches at the very top and few leaves. I did pull the grass back and will continue to do so, and will try to mulch them each year.

Thanks again for your advice.

I would be tempted to dig up the tree that's in worse shape after it's gone dormant to look at the roots. Often failure to thrive has to do with poor planting procedures or poor root structure. I'd use the hose to wash off as much dirt as I could. Look for circling roots, girdling roots, or a mass of sawdust in the middle (I figured out that was why my Arbutus X 'Marina' died. It wasn't too cold, it was too wet). If you don't want to dig it up, at least check to see if it the flare is buried. That means it was planted too deeply.

A lot of magnolias in this area need to be fertilized. It can take multiple applications of a nitrogen source before the desired level of improvement starts to be seen. Deep, moist fertile soil is what these woodland trees want.

Whatever other factors might have been involved with your specimen 'Marina' is tender, two years ago there was much damage to plantings in the Seattle area. One supplier of it in California says on the internet they know it can take 15 degrees F. based on what they had seen down there. Hardy to at least 15 may be impressive or at least acceptable for coastal CA, but up here that is not an adequate assurance.

Arbutus are basically trees of warm dry climates and situations, wetness and fungi are often problematic if a situation is not just right. Even the locally native madrones are having major problems these days on many sites.

My arbutus was next to the road where it got reflected heat, at the top of a retaining wall in sandy soil. Drainage should not have been a problem, but when I dug it up, it was all sawdust under the outer layer of soil and roots. There was little left in the way of roots. They'd all rotted. Linda Chalker-Scott recommends bare rooting your trees and shrubs before planting, and I can see why now.

Parking strips aren't noted for their good soil.
I would move those Star Magnolias as soon as possible. Take care though, as bboy noted, they can be difficult to move successfully.
Their white blooms in early spring are sure appreciated. When pruned, I like the open look.
Lack of fall color keeps them out of my garden. Hey, you have to draw the line somewhere.

A pink one would be good in front of one of your blue conifers.